Centrifugal compressor



7 Jan. 3, 1939. E. c. FURRER CENTRIFUGAL COMPRESSOR Filed Sept. 28, 1936VINVENTOR EMERY c. FURRER.

ATTORNEY Patented Jan. 3, 1939 UNITED STATES PATENT OFFlCE 6 Claims.

This invention relates to improvements in centrifugal compressors.

One object of the invention is to provide a centrifugal or turbocompressor for gases which is so constructed as to effect a reduction inenergy losses between stationary and moving parts by means of fluidseals between such parts.

Another object of the invention is to provide a centrifugal compressorhaving preferably a plurality of radially disposed spaced apartcompression chambers each of which is cooled by air moved between thesame by the rotary movement of the chambers.

A further object of the invention is to provide a rotary compressorarranged to draw the air, or other gas to be compressed, into themachine in opposite axial directions to effect a mutualcounter-balancing of the rapidly flowing incoming gases to reduce oreliminate shock losses caused thereby.

Other objects of the invention relate to various features ofconstruction and arrangement of parts which will be apparent from aconsideration of the following specification and accompanying drawingwherein:

Figure 1 is a side elevation of a centrifugal compressor embodying thepresent improvements.

Figure 2 is an enlarged sectional View taken on line 22 of Figure 1.

Figure 3 is a further enlarged broken vertical section taken on line 3-3of Figure 2.

Figure 4 is an enlarged broken vertical sectional view taken on line 44of Figure 2.

Figure 5 is an enlarged section taken on line 5-5 of Figure 3.

In Figure 1 of the drawing, the apparatus shown is mounted adjacent awall Ill of a building for support thereby and is provided with twoinlet ducts H and 2 for conveying to the compressor the air to becompressed. It will be understood that one or both such ducts may beconnected to a supply of other gas where such other gas is to becompressed by the machine.

The duct l connects at its inner end to a hollow shaft I3, see Fig. 3,which shaft is supported by upper and lower bearings l4 and I5. Theshaft i 3 is also provided with a pulley l6 around which operates a beltll extending to an electric motor It or other source of power foreffecting the rotation. of the shaft. The duct I2 is of considerablygreater diameter than duct H and bearing I5 is supported therein by anysuitable means as by beam I511.

Extending from the hollow shaft I3 are a plurality of radially disposedcompression chambers I 9 which decrease in cross sectional area from theinner to the outer ends thereof. The chambers l9 are spaced apart toprovide passages for the flow of cooling air around the chambers and areprovided with heat radiating or cooling fins l9a.

The upper and lower ends of the shaft l3 are provided with blades 20which are somewhat fan shaped and which are shaped at their edges tomove the air from the ducts H and i2 inwardly toward a centrallyarranged deflecting plate 2|. The blades also provide a structuralsupport for the shaft I3, the inner ends of the blades being united to acentral shaft or core. 22. Itwill be observed that as the shaft I3rotates, air will be drawn from the ducts l l and I2 inwardly througheach end of the shaft toward the deflector plate 2| which directs theair radially into the various compression chambers l9. Due to thedecreasing cross sectional area of the chambers is, the air iscompressed under the influence of the centrifugal force developed by therapidly rotating chambers and passes from the chambers into a hollow rimor annular connecting member 23 which unites the chambers at their outerends.

As is shown in Fig. 2, the portions 23a of the rim 23 between adjacentarms decrease in cross sectional area from the forward ends to the rearends thereof, the structure being designed for rotation in acounter-clockwise direction as viewed in Fig. 2. Air in passing from thechamhers I!) into the Various rim sections 23a is consequently furthercompressed and passes from the rim into air receivers 24, two of whichare shown, which terminate in ducts 25 which convey the compressed airto a place of storage or use. The receivers 24 are stationary anddecrease in cross sectional area from the outlet ends which areconnected to the conduits 25.

The rim sections 23a preferably are provided with a number of spacedapart walls or partitions 23b between which the air passes in flowingfrom the ends of the chambers l9 into the receivers 24.

The hollow rim 23 is, as shown in Fig. 4, provided on its upper surfacewith three annular walls 21, 28 and 29, the first two of which are shownas being slightly curved at their extremities. Each receiver 24 isprovided with a neck 24a, which is somewhat enlarged at its innerperiphery and terminates in a horizontal wall 241) which is providedwith oppositely curved depending annular walls 30 and 3]. It will beseen that between walls 21 and 28 a chamber 32 is provided in whichsealing liquid may be retained and which in cooperation with the walls21 and 30 will pro- Vide a seal to prevent the escape of compressed airthrough the space between the outer periphery of the rim and theadjacent portion of the receiver.

Between walls 28 and 29 another chamber 33 is provided for retainingsealing liquid which in cooperation with walls 28 and 3| will provide afurther seal against the escape of compressed gas. The rim is alsoprovided with depending walls 34 and 35 which project into the spaces orliquid chambers defined by walls 36, 31 and 38 which are carried by thenecks 24a of the receivers 24. The lower extremities of the walls 34 and35 are shown as being provided with thin plates 39 which extend intoclose proximity with the walls 40 which connect the walls 36, 31 and 38to break up and reduce eddy currents in the liquid during the rapidrotation of the compressor.

It will be apparent that the thin plates 39 will wear away readilyshould they contact the wall 40 and that the plates therefore can be setinitially close to the wall 40 without subsequent damage to the partsshould they contact during operation. It will be noted that while theupper and lower fluid seals shown in section in Fig. 4 are similar inprinciple, they differ slightly in structural detail for the reason thatthe fluid of the upper seal is carried by the rotary structure, whilethe fluid of the lower seal is carried by members supported by thestationary receivers.

It will be observed that as the rotary structure of the compressor isoperated air will be drawn into the ducts H and I2 partially by the fanaction of the blades 20 and partially by the centrifugal action of theair initially present in the structure. The air will move radiallythrough the compression chambers l9 and be compressed as it is forced totravel by centrifugal action through the constantly reduced crosssectional area of the chambers. It then passes from the chambers intothe rim sections between the walls 23b thereof and is thence directedbetween blades 24c disposed in the neck 24a of the receivers 24. Thestationary blades 240 are so disposed as to effect a reaction on the airissuing from the rim and converts the velocity head into pressure headas it passes into the receivers 24.

During such rotation of the apparatus the liquid in the respect vesealing chambers tends to move rad ally outward y or to the left as viewd in F gure 4 by the centrifugal action of the machine and will assumesubstantiallv the positions indicated in Fig. 4 in which positions itwill be noted that compressed air cannot escape between the rim and thereceivers. The greater the back pressure of the air due to centrifugalaction, the greater will be the resisting force exerted by the liquid.The fluid sealing means described not only provides an adequate sealbetween the relatively movable parts of the apparatus, but greatlyreducesenergy losses due to friction. V

The chambers I 9 are provided on their outer walls with horizontalblades 4| as shown in Fig. 5.

which are shaped to produce an inward flowof air through the duct l2 andupwardly into heat transfer relation with the surfaces of the chambersl9 and the fins l9a to absorb the heat of compression generated by thecompression of the air. Stationary vanes 42 preferably are secured tothe interior of the duct l2 to deflect the air in the direction ofrotation of the chambers to reduce shock.

To avoid the transfer of heat to the duct l i from the rising air asheath 43 is provided around the duct as shown in Figs. 1 and 3.

In operation the compressor is operated at the velocity required toeffect the desired compression of the air or the other gas. Due to thedual intake arrangement whereby the incoming air flows in oppositedirection through the equal capacity intake ends of the shaft I3 to thecenter of the machine toward the distributor plate 2|, the shock orthrust of the incoming air is balanced at all speeds of operation. Itwill also be noted that increasing the rotary velocity of the machine toincrease its output of compressed air or the degree of compressionthereof, increases also the flow of air around the exterior of thecompression chambers to absorb the increased heat of compression andthat increase in back pressure due to velocity, which tends to effectescape of air between the annular rim 23 and the annular receiversincreases the resistance of the fluid in the sealing chambers to resistsuch tendency;

It will be understood that if a gas other than air is to be compressed,the duct H and the thereto axially of the structure and in oppositedirections, radially disposed rotary compression chambers communicatingwith said intakes and provided with passages for the flow of cooling airbetween adjacent chambers, and a stationary receiver for receiving gascompressed by the chambers and provided with an elongated arcuate intakedisposed in communication with the outer ends of said chambers, saidreceiver having cross-sectional areas increasing progressively in thedirection of rotation of said chambers.

2. A gas compressor comprising a rotary structure, means for rotatingthe same, said structure having an axial gas intake and radiallyarranged compression chambers communicating therewith for centrifugallycompressing gas flowing into the same, a gas receiver having anelongated arcuate intake communicating with the ends of said chambers,and means for effecting the flow of air axially of the structure betweensaid chambers for absorbing the heat of compression of the gas therein.7

3. A gas compressor comprising a rotary structure having an axial gasintake, a plurality of radially arranged rotary gas compression chamberscommunicating therewith, an annular hollow rim communicating with andconnecting the outer ends of said chambers and provided with an openouter periphery, the segments of said rim between adjacent chambersdecreasing in cross sectional area from the forward to the rear ends ofsaid segments, a stationary gas receiver disposed adjacent the outeropen periphery of saidrim for receiving gas therefrom, and inter-leavingprojections carried by adjacent portions of said rim and receiverdefining annular fluid-confining channels for a fluid to prevent escapeof gas in the passage of the same from said rim to said receiver.

4. A gas compressor comprising a rotary structure having an axial gasintake, a plurality of radially disposed rotary chambers communicatingwith said intake, a hollow rim connecting the outer ends of saidchambers and communicating therewith, said chambers from the inner tothe outer ends thereof and the sections of said rim between adjacentchambers from the forward to the rear ends thereof decreasing incrosssectional area for effecting the compression of the gas forcedcentrifugally therethrough, and a stationary gas receiver communicatingwith said rim.

5. A gas compressor comprising a rotary structure provided with a hollowshaft disposed axially of the structure and provided with a gas intakeat each end thereof, a plurality of spaced apart radially disposedcompression. chambers communicating with said shaft, a hollow rim connected to and communicating with the outer ends of said chambers andprovided with an open outter periphery, stationary annular receivingmeans communicating with the open periphery of said rim, fluid sealingmeans comprising cooperating stationary and rotary portions carriedrespectively by said receiving means and said rim, to prevent escapetherebetween of cornpressed gas, and blades carried by said chambers foreffecting the circulation of air between the latter for absorbing heatgenerated by the compression of the gas therein.

6. In a gas compressor, a rotary structure comprising a plurality ofradially arranged compression chambers decreasing in cross sectionalarea from the inner to the outer ends thereof for compressing gaspassing therethrough, said structure being provided with an axial gasintake common to said chambers, an annular sta tionary gas receiverhaving a gas receiving passage in its inner periphery, and a continuoushollow rim at the outer ends of said chambers provided with an outerannular outlet in sealed communication with the gas receiving passage ofsaid receiver for transferring compressed gas from said chambers to saidreceiver.

EMERY C. FURRER.

